In Vivo Dynamic Lumbar Vertebral Motion and Disc Deformation During Lifting Tasks

举重任务期间的体内动态腰椎运动和椎间盘变形

• 批准号: 8191431
• 负责人: XUDONG ZHANG
• 金额: $ 20.01万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8191431
• 关键词: Vivo; Dynamic; Lumbar; Vertebral; Motion

DESCRIPTION (provided by applicant): Low back disorders (LBDs) remain one of most prevalent, debilitating, and costly occupational health problems in the United States. Mechanical loading on the lumbar spine is a central factor in the causation and prevention of occupational LBDs. The existing knowledge and methodological bases for evaluating mechanical forces on the lumbo-sacral (L5-S1) inter-vertebral disc were largely developed from static and/or in vitro cadaveric studies, or from in vivo dynamic studies that did not determine the internal vertebral movement or disc deformation. They are limited in their applicability in assessing the low back disorder or injury risks associated with dynamic work activities such as manual load lifting. Our overarching hypothesis is that more accurate understanding of the dynamic responses of lumbar spine during load-lifting will lead to more effective prevention and control of LBDs. The objective of this exploratory study is to characterize the relationships between dynamic responses of the lumbar spine and lifting dynamics defined by the load and lifting kinematics (i.e., dynamic postures), and begin to develop an improved model for evaluating the low back mechanical stress associated with manual tasks. The study will take advantage of a state-of-the-art dynamic radiographic system capable of measuring lumbar vertebral kinematics in vivo with unprecedented accuracy, and our extensive experience of studying the biomechanics of load lifting. We will pursue two specific aims: Aim 1 is to characterize the relationship between lumbar vertebral kinematics and dynamic lifting posture and the effect of load lifted on the relationship; we will acquire data of the lumbar vertebral kinematics using the dynamic X-ray system and the whole-body lifting kinematics using a motion capture system during the performance of lifting tasks. Aim 2 is to characterize the dynamic relationship between L5-S1 disc deformation and compressive force distribution; we will create a novel "spring-loaded wobbling platform" model to characterize this relationship and specify it empirically using data obtained from Aim 1; we will compare the L5-S1 disc compressive forces determined based on the new dynamic relationship and by the conventional approach which does not take into account the dynamic disc deformation. The proposed project is the first attempt to investigate the truly dynamic and in vivo mechanical behavior of the lumbar spine during lifting activities. It will pave the way for developing much improved capabilities to assess or predict low back mechanical stress during dynamic manual lifting. It will also afford a unique opportunity to establish new criteria (e.g., in vivo strain-based instead of stress-based) for disc tissue tolerance/failure. This work, along with a series of systematic studies that would naturally follow, will lead to a new body of knowledge and next-generation guidelines, models, and tools for better recognition, evaluation, and control of the risk of occupational low back disorders. PUBLIC HEALTH RELEVANCE: Mechanical loading on the lumbar spine is a central factor in causing and preventing low back disorders (LBDs) which are one of the leading occupational health problems. The existing knowledge and tools for evaluating the spinal loading are based on studies having only limited relevance and applicability to real work activities such as load lifting. The proposed research will develop new scientific knowledge and tools for more accurate assessment of the risk of LBDs associated with load lifting tasks.

描述（由申请人提供）：在美国，下背部疾病（LBD）仍然是最普遍、最令人衰弱和最昂贵的职业健康问题之一。腰椎上的机械负荷是职业性LBD的病因和预防的核心因素。评价腰骶椎（L5-S1）椎间盘上机械力的现有知识和方法学基础主要来自静态和/或体外尸体研究，或来自体内动态研究，这些研究未确定椎体内部运动或椎间盘变形。它们在评估与动态工作活动（如手动举重）相关的下背部疾病或损伤风险方面的适用性有限。我们的总体假设是，更准确地了解腰椎在负重过程中的动态反应，将导致更有效的预防和控制LBD。这项探索性研究的目的是描述腰椎的动态响应与由负荷和提升运动学定义的提升动力学之间的关系（即，动态姿势），并开始开发用于评估与手动任务相关的下背部机械应力的改进模型。这项研究将利用一个国家的最先进的动态放射摄影系统，能够测量腰椎运动学在体内前所未有的准确性，和我们的丰富经验，研究生物力学的负荷提升。我们将追求两个具体目标：目标1是表征腰椎运动学和动态提升姿势之间的关系，以及提升的负载对这种关系的影响;我们将在执行提升任务期间使用动态X射线系统和使用运动捕捉系统获取腰椎运动学数据。目标2是描述L5-S1椎间盘变形和压缩力分布之间的动态关系;我们将创建一个新的“弹簧加载摇摆平台”模型来描述这种关系，并使用目标1获得的数据来经验性地指定它;我们将比较L5-S1基于新的动态关系和通过不考虑动态盘的传统方法确定的盘压缩力变形该项目是首次尝试研究腰椎在举重活动中的真实动态和体内力学行为。它将为开发更好的能力铺平道路，以评估或预测动态手动提升过程中的下背部机械应力。它还将提供一个独特的机会来建立新的标准（例如，体内基于应变而不是基于应力）用于椎间盘组织耐受性/失效。这项工作，沿着一系列系统的研究，自然会随之而来，将导致一个新的知识体系和下一代的指南，模型和工具，更好地识别，评估和控制职业性腰痛疾病的风险。 公共卫生关系：腰椎上的机械负荷是引起和预防下背部疾病（LBD）的核心因素，下背部疾病是主要的职业健康问题之一。现有的用于评估脊柱负荷的知识和工具是基于对真实的工作活动（例如负荷提升）仅具有有限相关性和适用性的研究。拟议的研究将开发新的科学知识和工具，以更准确地评估与举重任务相关的LBD风险。